Pickering stabilization of thymol through green emulsification using soluble fraction of almond gum : whey protein isolate nano-complexes

In this study, the soluble fraction of almond gum (SFAG) as a sustainable biopolymer source and whey protein isolate (WPI) were used for self-assembly preparation of SFAG-WPI nano-complexes through electrostatic interaction. The SFAG was characterized using H-1 and C-13 NMR. The influence of total biopolymer concentration (0.2-0.4 %w/v) and ratios (1:3-3:1) as well as of the pH (2-6) on the formation of complexes was established by visual, light scattering, surface charge, and spectrometric observations. The outcomes proved the formation of negatively charged soluble complexes in the range of pH 4-5 and insoluble complexes at pH values 3 to 4. The soluble coacervate particles at pH 4.5 and total concentration of 0.4 %w/v were selected to induce Pickering stabilization of thymol. The static light scattering with microscopy studies (CLSM and Cryo-SEM) showed the formation of thymol oil-in-water emulsions by adsorption of nano-complexes on the surface of the droplets. Thymol emulsions stabilized using complexes had no size variation under storage (40 days) with an opaque and homogenous appearance. On the other hand, the emulsions containing solely WPI at pH 4.5 showed a substantial droplet size increase with severe creaming. Droplet size analysis together with coalescence and flocculation indices presented that coalescence was mainly responsible for droplet size coarsening of the emulsions stabilized by native WPI at pH 4.5. Overall, our outcomes indicated the improvement of WPI in the stabilization of emulsions through complexation

Recent advances in food colloidal delivery systems for essential oils and their main components

Background: Recently, the production of 'clean label' products as a potential strategy to eliminate the generation and utilization of synthetic ingredients (particularly preservatives) requires a lot of attention in different industries, including the food industry. Plant-based compounds, including essential oils (EOs), as well as their main components, have attracted great interest owing to their known characteristics, such as their antimicrobial and antioxidant activity. These lipophilic compounds, however, need to be incorporated into a delivery system to improve their functionality, application and consumer perception. Many different colloidal systems can be used as promising carriers to deliver EOs to food products. Scope and approach: In this review, the current state-of-the-art in the formulation of colloidal delivery systems for food products to encapsulate EOs is reviewed and their pros and cons in terms of formulation and functionality are given. Ultimately, some real food applications of different formulations are introduced. Key findings and conclusions: Oil-in-water nanoemulsions and nanoparticles loaded with EOs are the most commonly utilized delivery systems particularly for the food industry. Recent research is more focused on the design of novel carrier systems, including surfactant-based systems, fibers, films, and oleogels. Nevertheless, there is still a lack of research about the physicochemical stability as well as the functionality of delivery systems when they are embedded in a complex matrix of food ingredients. EO-loaded colloidal dispersion has the potential to be efficient partial or complete alternatives for synthetic preservatives depending on the final product, the characteristics of the delivery system, and food regulations